PITTSBURGH — Bilal Nichols and Greg Gilmore added to the Steelers’ stream of late-round draft prospects visiting the team as the defensive linemen came to the UPMC Rooney Sports Complex on Monday.

Nichols, out of Delaware, is a projected Day 3 selection while Gilmore, a former LSU player, is expected to be picked very late in the draft, if at all. He was not invited to the NFL Combine.

Finishing his four-year collegiate career in a 3-4 set, the 6-foot-4, 306-pound Nichols compiled 56 total tackles and 5.5 sacks. He would likely be competing with Javon Hargrave for nose tackle playing time in Pittsburgh should the team draft him.

Defensive ends Tyson Alualu and L.T. Walton can also play the position.

Gilmore, also an interior lineman, was a two year starter who tallied 53 total tackles, including 10 for a loss and 7.5 sacks in his senior season.

Mike Tomlin has made clear that base defense is a largely irrelevant concept in the modern NFL. Pittsburgh is nominally a 3-4 team, but often fields just two defensive linemen. Tomlin has said the team plays sub-package defense at least 75 percent of the time.

Those two defensive linemen are often “ends” Cameron Heyward and Stephon Tuitt, who take up positions that traditional defensive tackles would. Most any defensive lineman the Steelers select or sign would likely be asked to fill such a role — unless he is a pure nose tackle.